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DISCUSSION OF DIZZINESS
Dizziness is a symptom not a disease. It may be defined as
a sensation of unsteadiness, imbalance, or disorientation
in relation to an individual's surroundings. The symptom of
dizziness may vary widely from person to person and be caused
by many difference diseases. It varies from a mild unsteadiness
to a severe whirling sensation known as vertigo. As there
is little representation of the balance system in the conscious
mind, it is not unusual for it to be difficult for the patient
to describe his symptom of dizziness to the physician. In
addition, because the symptom of dizziness varies so widely
from patient to patient and may be caused by many different
diseases, the physician commonly requires testing to be able
to provide the patient with some knowledge about the cause
of his dizziness. Dizziness may or may not be accompanied
by a hearing impairment
FUNCTION OF THE NORMAL EAR
The ear is divided into three parts: external ear, middle
ear, and inner ear.
The external ear structures gather sound and direct it toward
the eardrum. The middle ear chamber consists of an eardrum
and three small ear bones. These structures transmit sound
vibrations to the inner ear fluid.
The inner ear chamber (labyrinth) is encased in bone and filled
with fluid (endolymph and perilymph). This fluid bathes the
delicate nerve endings of the hearing and the balance mechanism.
Fluid waves in the hearing chamber (cochlea) stimulate the
hearing nerve endings which generate an electrical impulse.
These impulses are transmitted to the brain for interpretation
as sound. Movement of fluid in the balance chambers (vestibule
and three semicircular canals) also stimulates nerve endings,
resulting in electrical impulses to the brain, where they
are interpreted as motion.
MAINTENANCE OF BALANCE
The human balance system is made up of four parts. The brain
acts as a central computer receiving information in the form
of nerve impulses (messages) from its three input terminals:
the eyes, the inner ear, and the muscles and joints of the
body. There is a constant stream of impulses arriving at the
brain from these input terminals. All three systems work independently
and yet work together to keep the body in balance.
The eyes receive visual clues from light receptors that give
the brain information as to the position of the body relative
to its surroundings. The receptors in the muscles and joints
are called proprioceptors. The most important ones are in
the head and neck (head position relative to the rest of the
body) and the ankles and joints (body sway relative to the
ground).
The inner ear balance mechanism has two main parts: the three
semicircular canals and the vestibule. Together they are called
the vestibular labyrinth and are filled with fluid. When the
head moves, fluid within the labyrinth moves and stimulates
nerve endings that send impulses along the balance nerve to
the brain. Those impulses are sent to the brain in equal amounts
from both the right and left inner ear. Nerve impulses may
be started by the semicircular canals when turning suddenly,
or the impulses may come from the vestibule, which responds
to changes of position, such as lying down, turning over or
getting out of bed.
When one inner ear is not functioning correctly the brain
receives nerve impulses that are no longer equal, causing
it to perceive this information as distorted or off balance.
The brain sends messages to the eyes, causing them to move
back and forth, making the surroundings appear to spin. It
is this eye movement (called nystagmus) that creates a sensation
of things spinning.
Remember to think of the brain as a computer with three input
terminals feeding it constant up-to-date information from
the eye, inner ear and muscles and joints (proprioceptors).
The brain itself is divided into several different parts.
The most primitive area is known as the brainstem, and it
is here that processing of the input from the three sensory
terminals occurs. The brainstem is affected by two other parts
of the brain, the cerebral cortex and the cerebellum.
The cerebral cortex is where past information and memories
are stored. The cerebellum, on the other hand, provides automatic
(involuntary) information from activities which have been
repeated often.
The brainstem receives all these nerve impulses: sensory from
the eyes, inner ear, muscles and joints; regulatory from the
cerebellum; and voluntary from the cerebral cortex. The information
is then processed and fed back to the muscles of the body
to help maintain a sense of balance.
Because the cortex, cerebellum and brainstem can eventually
become used to (ignore) abnormal or unequal impulses from
the inner ear, exercise may be helpful. Exercise often helps
the brain to habituate to (get used to) the dizziness problem
so that is does not respond in an abnormal way, does not result
in the individual feeling dizzy. An example of habituation
is seen with the ice skaters who twirl around, stop suddenly,
and do not apparently have any balance disturbance.
TYPES OF DIZZINESS
Sensations of unsteadiness, imbalance or disorientation in
relationship to one's surroundings may result from disturbances
in the ear, neck, muscles and joints, the eyes, the nervous
system connections of these structures, or a combination of
any of the above.
Ear Dizziness
Ear dizziness, one of the most common types of dizziness,
results from disturbances in the blood circulation or fluid
pressure in the inner ear chambers, from direct pressure on
the balance nerve, or physiologic changes involving the balance
nerve. Inflammation or infection of the inner ear or balance
nerve is also a major cause of ear dizziness.
The inner ear mechanism is about the size of a pea, and is
extremely sensitive. There are two inner ear chambers: One
for hearing (cochlea), and one for balance (vestibule and
semicircular canals). These chambers contain a fluid which
bathes the delicate nerve endings. These nerve endings are
stimulated when there is movement of the fluid. Nerve impulses
are then transmitted to the brain by the hearing and balance
nerves. The nerves pass through a small bony canal (internal
auditory canal), accompanied by the facial nerve.
Any disturbance in pressure, consistency or circulation of
the inner ear fluids may result in acute, chronic, or recurrent
dizziness, with or without hearing loss and head noise. Likewise,
any disturbance in the blood circulation to this area or infection
of the region may result in similar symptoms. Dizziness may
also be produced by over stimulation of the inner ear fluids,
such as one encounters when he spins very fast and then stops
suddenly.
Central Dizziness
Central dizziness is usually an unsteadiness brought about
by failure of the brain to correctly coordinate or interpret
the nerve impulses which it receives. An example of this is
the "swimming feeling" or unsteadiness that may
accompany emotional stress, tension states, and excessive
alcohol intake. Circulatory inefficiency, tumors, or injuries
may produce this type of unsteadiness, with or without hearing
impairment. A feeling of pressure or fullness in the head
is common. Occasionally true vertigo (spinning) may be caused
by central problems.
Neck Dizziness
Neck Dizziness (cervical vertigo) results from abnormal or
uncoordinated nerve impulses being sent to the brain from
the neck muscles.
The neck muscles are constantly sending nerve impulses to
the balance centers of the brain to help maintain equilibrium.
Spasm (tenseness) of the muscles may result in an abnormal
nerve discharge, leading to unsteadiness or dizziness. This
spasm may result from injury, arthritis of the spine, or from
pressure on nerves in the neck.
Muscle-Joint Dizziness
Muscle-joint dizziness is relatively uncommon. Any disturbance
of sensation arising from the muscles and joints in the limbs
(such as occurs in the muscular dystrophies and other abnormalities)
produces this type of unsteadiness. Such an example is the
unsteadiness experienced when one tries to walk on a leg that
has "gone to sleep."
Visual Dizziness
Eye Muscle imbalance or errors of refraction may produce unsteadiness.
An example of this is the unsteadiness which may result when
one attempts to walk while wearing glasses belonging to another
individual.
Another example of visual dizziness is that occasionally produced
if one is seated in a car looking out the side window at passing
objects. The eyes respond by sending a rapid series of impulses
to the brain indicating that the body is rotating. On the
other hand, the ears and the muscle-joint systems send impulses
to the brain indicating that the body is not rotating, only
moving foreword. The brain, receiving these confused impulses
(from the eyes indicating rotation, from the ears and muscle-joint
systems indicating forward motion) sends out equally confusing
orders to various muscles and glands that may result in sweating,
nausea and vomiting. When one sits in the front seat looking
forward, the eyes, ears, and muscle- joint systems work more
uniformly and one is less likely to develop car sickness.
A visual disturbance may be caused by dizziness from other
sources. Intermittent inability to focus the eyes, difficulty
reading or intermittent blurring of vision, although at times
the result of anxiety or tension may result from small reflex
movements of the eye called nystagmus. This nystagmus is common
during severe dizziness.
WARNING
Persons subject to dizziness should exercise caution when
swimming. Buoyancy of the water results in an essentially
weightless condition, and visual orientation is greatly impaired
if one's head is under water. As a result, orientation depends
almost entirely on the inner ear balance canals. An attack
of dizziness at this time could be very dangerous. Similarly,
individuals who have lost both inner ear balance canals should
avoid underwater swimming.
EAR DIZZINESS: SYMPTOMS
Any disturbance affecting the function of the inner ear or
its central connections may result in dizziness, hearing loss
or tinnitus (head noise). These symptoms may occur singly
or in combination, depending upon which functions of the inner
ear are disturbed.
Ear dizziness may appear as a whirling or spinning sensation
(vertigo), unsteadiness, or giddiness and lightheadedness.
It may be constant, but is more often intermittent, and is
frequently aggravated by head motion or sudden positional
changes, nausea and vomiting may occur, but one does not lose
consciousness as a result of inner ear dizziness.
DIAGNOSING THE CAUSE OF DIZZINESS
Dizziness may be caused by any disturbance in the inner ear,
the balance nerve or its central connections. This can be
due to a disturbance in circulation, fluid pressure or metabolism,
infections, neuritis, drugs, injury, or growths.
At times an extensive evaluation is required to determine
the cause of dizziness. The tests necessary are determined
at the time of examination and may include detailed hearing
and balance tests, x-rays, and blood tests. A general physical
examination and neurological tests may be advised.
The object of this evaluation is to be certain that there
is no serious or life-threatening disease, and to pinpoint
the location of the problem. This lays the groundwork for
effective medical or surgical treatment.
CIRCULATION CHANGES
Any interference with the circulation to the delicate inner
ear structures or their central connections may result in
dizziness and, at times, hearing loss and tinnitus. These
circulatory changes may be the result of blood vessel spasm,
partial or total occlusion (blockage), or rupture with hemorrhage.
Atypical Migraine or Basilar Migraine
Inner ear dizziness due to blood vessel spasm is usually sudden
in onset and intermittent in character. It may occur as an
isolated event in the patient's life or repeatedly in association
with other symptoms. If it is recurrent it usually is associated
with migraine headache-type symptoms. Predisposing causes
include fatigue and emotional stress. Certain drugs such as
caffeine (coffee) and nicotine (cigarettes) tend to produce
blood vessel spasm or constriction and should be avoided.
Blood vessel spasm has been noted to occasionally begin after
head injury. Although there may have been no direct injury
to the inner ear by the trauma, the spasm may begin to damage
the ear.
Occlusion
As one gets older, blood vessel walls tend to thicken due
to an aging process known as arteriosclerosis. This thickening
results in partial occlusion, with a gradual decrease of blood
flow to the inner ear structures. The balance mechanism usually
adjusts to this, but at times persistent unsteadiness develops.
This may be aggravated by sudden position changes such as
that encountered when one gets up quickly or turns suddenly.
Complete occlusion of an inner ear blood vessel (thrombosis)
results in acute dizziness often associated with nausea and
vomiting. Symptoms may persist for several days, followed
by a gradual decrease of dizziness over a period of weeks
or months as the central nervous system and uninvolved ear
compensates for the loss of the involved ear.
Hemorrhage
Occasionally one of the small blood vessels of the balance
mechanism ruptures. This may occur spontaneously, for no apparent
reason, or it may be the result of high blood pressure or
head injury. Symptoms are the same as those of occlusion.
Treatment
Treatment of dizziness due to changes in circulation consists
of anti-dizziness medications to suppress the symptoms. They
also stimulate the circulation and enhance the effectiveness
of the brain centers in controlling the symptoms. An individual
with this type of dizziness should avoid drugs that constrict
the blood vessels, such as caffeine (coffee) and nicotine
(tobacco). Emotional stress, anxiety and excessive fatigue
should be avoided as much as possible. Often, increased exercise
will aid in the suppression of dizziness in many patients
by stimulating the remaining function to be more effective.
BENIGN POSITIONAL VERTIGO
Postural or Positional Dizziness
Postural or positional dizziness is a common form of balance
disturbance due to circulatory changes or to loose calcium
deposits in the inner ear. It is characterized by sudden,
brief episodes of imbalance when moving or changing head position.
Commonly it is noticed when lying down or arising or when
turning over in bed. This type of dizziness is rarely progressive
and usually responds to treatment, but it may recur. Treatment
usually consists of exercises designed to provoke the dizziness
until it fatigues. This type of exercise may be recommended
by your physician to cause the positional dizziness to run
its course more quickly. Occasionally, postural dizziness
may be permanent and surgery may be required.
IMBALANCE RELATED TO AGING
Some individuals develop imbalance as a result of the aging
process. In many cases this is due to circulatory changes
in the very small blood vessels supplying the inner ear and
balance nerve mechanism. Fortunately, these disturbances,
although they may persist, rarely become worse.
Postural or positional vertigo (see above) is the most common
balance disturbance of aging. This may develop in younger
individuals as a result of head injuries or circulatory disturbances.
Dizziness on change of head position is a distressing symptom,
which is often helped by vestibular exercises.
Temporary unsteadiness upon arising from bed in the morning
is not uncommon in older individuals. At times this feeling
of imbalance may persist for an hour or two. Arising from
bed slowly usually minimized the disturbance. Unsteadiness
when walking, particularly on stepping up or down, or walking
on uneven surfaces, develops in some individuals as they progress
in age. Using a cane and learning to use the eyes to help
the balance is often helpful.
INFECTION
Symptoms
Imbalance due to ear infection is usually insidious and mild
in onset. Such imbalance may occur with or without hearing
impairment. As the infection gets closer to the vital balance
mechanism in the inner ear, the dizziness becomes more constant
and severe in nature, and is often associated with nausea
and vomiting.
Treatment
Control of an ear infection is imperative in this type of
dizziness in order to prevent spread of the infection directly
into the balance center of the inner ear. Should this develop,
serious complications including total loss of hearing in the
involved ear may result. If the infection cannot be eliminated
by medical treatment, surgery is indicated to remove the infection.
NEURITIS
Neuritis is a physiological change which occurs in the nerve
after injury by trauma, a virus, autoimmune disease, or vascular
compression. When this occurs, the balance function is impaired,
resulting in a severe, and at times prolonged, episode of
dizziness, often followed by some unsteadiness or motion for
weeks to years. Fortunately, this balance disturbance usually
subsides in time and usually does not recur in the majority
of cases. It may be, however, very chronic at a moderate to
mild level. Medical treatment is helpful in eliminating symptoms
until the central nervous system can compensate for the injured
nerve. This usually consists of dizziness- suppressing drugs.
On occasion, the central nervous system cannot compensate
and surgery may be necessary
METABOLIC DISTURBANCES
Occasionally metabolic disturbances produce dizziness with
or without associated hearing loss by interfering with the
function of the inner ear or the central nervous system. Occasionally
hearing loss may occur without the presence of dizziness.
A change of thyroid function or abnormalities in the blood
sugar are the most common metabolic disturbances resulting
in dizziness. Rarely, fat metabolism abnormalities may also
cause problems resulting in hearing loss and/or dizziness.
Thyroid dysfunction is diagnosed by blood tests and treatment
consists of taking a thyroid hormone. Abnormalities in the
blood sugar are diagnosed, again by blood studies, and treatment
usually consists of diet control and/or drug therapy. Fat
metabolism problems and diagnosed by studies of the fatty
acids and cholesterol in the blood. Treatment of these may
consist of diet control with or without drug therapy.
ALLERGIES
Rarely, allergies may cause dizziness and/or vertigo. Allergies
are usually diagnosed by obtaining a careful history and occasionally
performing a series of skin tests with inhalants and food,
and/or blood tests. Treatment usually consists of elimination
of the offending agents when possible, or, if this is not
possible, by allergy shots to stimulate immunity.
INJURY
Injury to the head occasionally results in dizziness of long-standing
origin. If the trauma is severe, it is usually due to the
combined damage to the inner ear, balance nerve, and central
nervous system. Lesser injury may damage any one, or a combination
of these components. The unsteadiness is at times prolonged,
and may or may not be associated with hearing loss and head
noise as well as other symptoms.
Trauma and Inner Ear Concussion
In head trauma the inner ear structures may be damaged by
the severe sudden shaking that occurs. The pressure in the
inner ear often begins to rise or calcium crystals may be
dislodged. There may also be bleeding into the inner ear.
This is called inner ear concussion. Although present over
a period of months, the dizzy symptoms will often subside,
but at times a mild persistent dizziness occurs. In other
patients a post-traumatic endolymphatic hydrops (Meniere's
disease) begin to develop some months to years after the injury.
In these cases continual medicine may be required, or surgery
may be necessary.
Trauma and Chronic Vestibular Neuritis
In more severe trauma, the balance and hearing nerve may be
sheared. This occurs when the skull suddenly stops and the
brain continues to move for a fraction of a second. The nerve
is damaged at the entrance to the temporal (ear) bone. Symptoms
are usually unresponsive to medical treatment and require
surgery.
Trauma and Brain Damage
Again in severe trauma the base of the brain and/or the cerebellum
may be injured. These structures are slow to heal and there
is often a residual dizziness that is severely resistant to
any treatment. Fortunately, the symptoms are usually relatively
mild and do not preclude some type of work. However, occasionally
they may be quite incapacitating. Medication is not often
beneficial, but rehabilitation therapy can be quite helpful.
A perilymphatic fistula is a leak of inner ear fluid into
the middle ear. Relatively minor closed head injuries may
cause a fistula, the fistula occurs at either the oval window
(window where the stapes bone fits) or the round window membrane
(an opening from the cochlea to the middle ear). Fistulas
change the pressure in the inner ear and lead to a variety
of symptoms, some of which can be incapacitating. Persistent
daily low grade dizziness is often associated with fistulas,
but the patient may also experience severe episodes of vertigo
similar to those seen in Meniere's disease. Surgery is usually
required to close a fistula and stop the symptoms. If the
fistula is large, or has been present for some time, there
may be permanent damage to the inner ear and symptoms may
persist even after closure of the fistula. In these cases
a vestibular nerve section is necessary to stop the persistent
dizziness.
TUMORS
A noncancerous tumor occasionally develops on the balance
nerve between the ear and the brain. When this occurs, unsteadiness,
hearing loss and head noise may develop. Extensive hearing evaluations, balance tests, and x-rays are necessary to diagnose
such tumors.
If the diagnosis of a tumor is established, surgical removal
is imperative. Continued growth of the tumor would lead to
complications by producing pressure on vital adjacent nerves
and the brain. An operation has been developed which allows
the removal of these tumors at an early stage. Best results
can be obtained if the tumor is diagnosed early and removed
while the only symptoms are hearing loss, dizziness, and tinnitus
(head noise).
Dandy's Syndrome
A total loss of inner ear balance function in both ears is
rare. It results in a condition called Dandy's syndrome. This
may result from infections, injuries or tumor removal. There
may be serious dizziness at the time the individual first
loses the balance mechanism. Other portions of the balance
mechanism (eyes, muscles and joints) help the individual to
compensate for the loss of inner ear function. Most do quite
well except in the dark or when swimming. Many notice oscillopsia,
a tendency for objects to appear to move up and down while
in motion.
There is no treatment for Dandy's syndrome. Most patients
compensate well and lead normal lives. One should avoid movement
in total darkness and avoid underwater swimming.
VASCULAR COMPRESSION SYNDROME
The vestibular (balance) nerve is located in a very complex
part of the skull called the posterior fossa. A number of
blood vessels are in close proximity to the nerve. If a blood
vessel happens to compress or pulsate against the vestibular
nerve, dizziness may result.
The diagnosis of this syndrome is difficult. A careful history
and the results of specialized auditory and balance tests
provide the physician with the suspicion of a vascular compression
syndrome. The treatment is microvascular vestibular nerve
decompression.
LABYRINTHINE DYSFUNCTION
Labyrinthine dysfunction describes one of the non-specific
conditions where the inner ear is not functioning properly.
Although the cause is often unknown, viral illnesses, medication,
and trauma are known at times to cause this condition. In
order to reach this diagnosis definitively, hearing and balance
testing must be done.
Symptoms may be highly variable. They can range from occasional
unsteadiness to episodic vertigo or constant unsteadiness.
Hearing loss is occasionally present.
Initially, treatment is medical and a wide variety of medications
may be used. Occasionally, vertigo exercises are helpful.
When vertigo cannot be controlled with medication or exercises,
surgery is sometimes indicated.
ENDOLYMPHATIC HYDROPS
Endolymphatic hydrops is a term which describes increased
fluid pressure in the inner ear. In this respect it is similar
but not related to glaucoma of the eye fluids. A special clinical
form of endolymphatic hydrops is called Meniere's disease,
described elsewhere in this book. All patients with Meniere's
disease have endolymphatic hydrops, but not all patients with
hydrops have Meniere's disease.
There may be many causes of endolymphatic hydrops. It occurs
widely in people of European decent and rarely in oriental
or black people. It may be caused or aggravated by excessive
salt intake or certain mediations. The symptoms are highly
variable. The patient may have one symptom or a combination.
Often there is a combination of hearing changes, disequilibrium,
motion intolerance, or short dizzy episodes. There may be
tinnitus and/or a pressure feeling in the head or ears. The
patient does not have the well defined attacks of Meniere's
disease (fluctuating hearing loss, tinnitus and episodes of
spinning lasting minutes to hours). Often the division between
the two diagnoses may be blurred and difficult to separate,
even for the patient. Endolymphatic hydrops may progress to
Meniere's disease in some patients.
The treatment of endolymphatic hydrops is similar to that
for Meniere's disease. Medications are first used. Diuretics
(water pills) are almost always used. Their purpose is to
decrease the fluid pressure in the inner ear. In addition
to diuretics, other medications may be indicated, depending
on the cause of symptoms in each patient's case. If these
fail, surgery is sometimes indicated. (See Surgery for vertigo
elsewhere in this document).
MENIERE'S DISEASE
Meniere's disease is a common cause of repeated attacks of
dizziness, and is thought to be due (in most cases) to increased
pressure of the inner ear fluids due to impaired metabolism
of the inner ear. Fluids in the inner ear chamber are constantly
being produced and absorbed by the circulatory system. Any
disturbance of this delicate relationship results in overproduction
of underabsorption of the fluid. This leads to an increase
in the fluid pressure (hydrops) that may, in turn, produce
dizziness which may or may not be associated with fluctuating
hearing loss and tinnitus.
A thorough evaluation is necessary to determine the cause
of Meniere's disease, if possible. Circulatory, metabolic,
toxic and allergic factors may play a part in any individual.
Emotional stress, while making the disease worse, does not
cause it.
Symptoms
Meniere's disease is usually characterized by attacks consisting
of vertigo (spinning) that varies in duration from a few minutes
to several hours. Hearing loss and head noise, usually accompanying
the attacks, may occur suddenly. Violent spinning, whirling,
and falling associated with nausea and vomiting are common
symptoms. Sensations of pressure and fullness in the ear or
head are usually present during the attacks. The individual
may be very tired for several hours after the overt spinning
stops.
Attacks of dizziness may recur at irregular intervals and
the individual may be free of symptoms for years at a time,
only to have them recur again. In between major attacks, the
individual may have minor episodes occurring more frequently
and consisting of unsteadiness lasting for a few seconds to
minutes.
Occasionally hearing impairment, head noise, and ear pressure
occur without dizziness. This type of Meniere's disease is
called cochlear hydrops. Similarly episodic dizziness and
ear pressure may occur without hearing loss or tinnitus, and
this is called vestibular hydrops.
Treatment of Meniere's Disease
Treatment of cochlear and vestibular hydrops is the same as
for classic Meniere's disease. The treatment of Meniere's
disease may be medical or surgical, depending upon the patient's
stage of the disease, life circumstances, and the condition
of the ears. The purpose of the treatment is to prevent the
hearing loss, and stop the vertigo (spinning).
It is aimed at improving the inner ear circulation and controlling
the fluid pressure changes of the inner ear chambers. At times
it is necessary to cut the balance nerve or remove the inner
ear structures.
Medical treatment of Meniere's disease varies with the individual
patient according to suspected cause and magnitude and frequency
of symptoms. It is effective in decreasing the frequency and
severity of attacks in 80% of patients. Treatment may consist
of medication to decrease the inner ear fluid pressure or
prevent inner ear allergic reactions. Various drugs are used
as anti-dizziness medication. Vasoconstricting substances
have an opposite effect and, therefore, should be avoided.
Such substances are caffeine (coffee) and nicotine (cigarettes).
Diuretics ("water pills") may be prescribed to decrease
the inner ear fluid pressure.
Meniere's disease may be caused or aggravated by metabolic
or allergic disorders. Special diets or drug therapy are indicated
at times to control these problems.
On rare occasions we may use gentamycin injections which selectively
destroy balance function. This treatment is reserved for patients
with Meniere's disease in their only hearing ear or with Meniere's
disease in both ears.
DIZZINESS: SURGICAL TREATMENT
Surgery is indicated when medical treatment fails to control
the vertigo. The type of operation selected depends on the
degree of hearing impairment in the affected ear, the life
circumstances of the individual, and the status of the individual's
disease. In some operations the hearing may be occasionally
improved following surgery, and in others it may become worse.
In most cases it remains the same. Head noise may or may not
be relieved, and in some cases may become even more marked.
In most cases it is not relieved.
Surgery is most successful in relieving acute attacks of dizziness
in the majority of patients. Some unsteadiness may persist
over a period of several months until the opposite ear and
the central nervous system are able to compensate and stabilize
the balance system.
Surgical Procedures Include:
GEndolymphatic Shunt
This operation drains excess endolymph from the inner ear.
It is usually performed under general anesthesia and requires
hospitalization for one to two days.
An incision is made behind the ear. A mastoid operation is
performed and a tube is inserted into the endolymphatic sac
of the inner ear to control the abnormal fluid pressure.
A shunt operation usually is advised when hearing is relatively
good in the involved ear. Further loss of hearing may occur
in 25% of cases due to progression of the disease. Total loss
of hearing in the operated ear following surgery is uncommon,
but does occur in about 3% of operations.
GTranslabyrinthine labyrinthectomy and section of
the vestibular (balance) nerve.
The operation is performed under general anesthesia and requires
hospitalization for approximately five to seven days. Through
an incision behind the ear, a mastoidectomy is performed,
the inner ear balance chambers are removed, and the balance
nerve is cut. In order to fill in the cavity where bone was
removed, a superficial incision made on the abDombn and a
small amount of fat is obtained and placed in the mastoid.
In cases selected for labyrinthectomy and section of the vestibular
nerve, hearing is severely impaired. The operation results
in total loss of hearing in the operated ear, and frequently,
a temporary increase in dizziness. Fortunately, the attacks
of dizziness are eliminated in nearly every instance. Persistent
unsteadiness, however, may continue for a period of weeks
or months until the central nervous system stabilizes the
balance system. When necessary, this operation can be performed
if other surgery is not successful.
Middle fossa section of the vestibular (balance) nerve
This procedure is performed under general anesthesia, and
usually requires five to seven days of hospitalization. Through
an incision above the ear, the balance nerve is cut before
it enters the inner ear chamber.
Middle fossa section of the vestibular nerve may be advised
when hearing is good in the involved ear. Up to 5% of patients
may develop a severe hearing impairment in the operated ear.
Fortunately, the attacks of dizziness are eliminated in nearly
every instance. Persistent unsteadiness, however, may continue
for a period of weeks or months until the central nervous
system stabilizes the balance system. Temporary paralysis
of half the body has occurred following a middle fossa nerve
section, due to brain swelling. This complication is, however,
extremely rare.
Retrosigmoid section of the vestibular (balance) nerve
This operation is performed in the hospital under general
anesthesia and requires hospitalization for about five to
seven days. Through an incision well behind the ear, the balance
nerve is cut before it enters the inner ear. In order to fill
in the cavity where bone was removed, a superficial incision
is made on the abDombn and a small amount of fat is obtained
and placed in the space where the bone was removed.
This procedure allows examination of the anatomy between the
inner ear and the brain, particularly the vessels. This operation
may be advised when the hearing is good in the involved ear,
and the patient is somewhat older. Up to 15% of patients may
develop a severe hearing impairment in the operated ear after
surgery. Fortunately, the attacks of dizziness are eliminated
in nearly every instance (90% - 95%). Persistent unsteadiness
may continue for several weeks to months until the central
nervous system has stabilized the balance system. Temporary
paralysis of half the body has occurred following a surgery
due to brain swelling. Fortunately, this complication is extremely
rare.
RISKS AND COMPLICATIONS OF SURGERY FOR DIZZINESS
Hearing Loss
Further hearing impairment in the operated ear may occur following
any of the procedures, and is the expected result following
some. This has been commented on for each procedure.
Tinnitus
Tinnitus (head noise) usually remains the same as before surgery.
If the hearing is worse following surgery, tinnitus may likewise
be more noticeable.
Taste Disturbance and Mouth Dryness
Taste disturbance and mouth dryness are not uncommon for a
few weeks following surgery. In 5% if the patients this disturbance
is prolonged.
Weakness of the Face
The facial nerve travels through the ear bone in close association
with the hearing and balance nerves, the inner ear and mastoid
(refer to the diagram). Temporary weakness of one side of
the face is an uncommon postoperative complication of ear
surgery. It may occur as the result of an abnormality or swelling
of the nerve. Permanent paralysis of the face is extremely
rare. Should it occur, however, eye complications could develop
requiring treatment by an eye specialist.
Spinal Fluid Leak
All of the operations described above can result in a leak
of cerebrospinal fluid (fluid surrounding the brain). Further
surgery may be necessary to stop it.
Infection
Infection is a rare occurrence following surgery for dizziness.
Should it develop, however, it could lead to meningitis (an
infection of the fluid surrounding the brain) and may require
prolonged hospital treatment. Fortunately, this complication
is very rare.
Hematoma
A hematoma (collection of blood under the skin incision) develops
in a small percentage of cases, prolonging hospitalization
and healing. Reoperation to remove the clot may be necessary
if this complication occurs.
DIZZINESS: NONSURGICAL TREATMENT
Vestibular Rehabilitation
Current retrospective studies indicate that 85% of patients
with chronic vestibular dysfunction gain at least partial
relief of their symptoms after undergoing vestibular rehabilitation.
Typically, a physical therapist evaluation of patients with
vestibular or balance disorders take approximately 60-90 minutes.
The evaluation begins with a history of the patient's symptoms.
This includes how long the patient has been symptomatic, how
long the symptoms last, general activity level and medications
that the patient is currently taking. Range of motion, strength,
coordination, balance and various sensory systems are also
assessed. Patients are asked to perform; transitional movements
such as rolling, supine to sit and sit to stand. This is to
determine whether these motions produce or increase symptoms.
One of the most difficult things for patients with vestibular
disorders to do is walk and move the head. Different combinations
of head and neck movements are performed during gait to provoke
symptoms. Balance is also tested on a firm surface and again
on a compressible surface with eyes open and closed. Time
tests of balance are performed with eyes open and closed,
while standing on one foot and with feet aligned as if on
a tightrope.
Following the evaluation, a treatment plan is developed. The
treatment consists of habitual exercises, balance retraining
exercise, and usually a general conditioning program. The
goal of habituation exercises is to decrease the patient's
symptoms of motion provoked dizziness or lightheadedness.
The exercises are chosen to address the patient's particular
problems that were discovered during the evaluation. These
exercises use repetitive movements or positional stimuli to
physiologically fatigue the response of the vestibular system.
This, in turn, increases the patient's tolerance for these
movements. Controlled provocation of symptoms with the home
program "desensitizes" the patient's response to
movements that previously stimulated dizziness. Patients that
have non-reproducible or spontaneous symptoms (ones that appear
unexpectedly and independently of whether the patient is moving);
do not respond as well to these exercises as a means to control
their symptoms. Balance retraining exercises are also given
when appropriate and consist of activities directed towards
improving the patient's balance. Exercises are chosen according
to the problem areas discovered in the evaluation and often
involve interaction among the three sensory inputs involved
in balance: vision, somatosensory cues and vestibular inputs.
Thus the patient may be asked to perform exercises with eyes
closed or standing on a compressible surface. A general conditioning
program usually consists of a walking program or another fitness
program that the patient is interested in. The length and
intensity of the general conditioning program depends upon
the patient's previous activity level and how easily their
symptoms are provoked. The patient must consistently perform
all the exercises as described in their treatment program
to achieve the goals of improving their balance and decreasing
their dizziness. Typically the exercises are performed twice
a day. Patients are advised not to avoid positions that provoke
symptoms unless they are unsafe.
Usually the patient is given a home exercise program to perform,
and asked to return to the office in two to four weeks for
a follow-up visit to monitor their progress and modify their
home program as necessary. If the patient lives very far way,
this can sometimes be done over the phone. Occasionally, if
the patient's problems are significant enough, he or she may
be asked to come into to office for balance/vestibular training
that can be supervised by the physical therapist.
SUMMARY
There are many causes of dizziness. This dizziness may or
may not be associated with hearing loss. In most instances
the distressing symptoms of dizziness can be greatly benefited
or eliminated by medical or surgical management.
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